Isolation of yeasts from soil 681
RESULTS
On pH 4 glucose peptone agar
There was very great site-to-site variation in numbers of soil yeasts. Counts
from single samples varied between 6000 and 240,000 yeast colonies/g. soil.
No seasonal trend in numbers was distinguishable. Four species, Cryptococcus
albidus (Saito) Skinner, Cryptococcus terrew di Menna, Candida cumata
(Diddens & Lodder) Lodder & van Rij and Schizoblastosporion starkeyihenricii
Ciferri occurred in important numbers; very few strains of other
species were recovered. Of these four species Cryptococcus terreus was the
commonest in most collections. Schizoblastosporion starkeyi-henricii made up
75 yo of the isolates from the three higher and drier sites sampled in May 1955,
but was represented in only small numbers in the five other soil collections.
Detailed results are given in Table 1.
Yeasts on pasture leaves showed a seasonal change of species pattern
(Table 2). In May (autumn) Sporobolornyces odorus Derx, Candida humicola
(Daszewska) Diddens & Lodder, and Schizoblastosporion starkeyi-henricii were
isolated from the washings, but none of these species was present in the
August and October (late winter and spring) collections, when Cryptococcus
laurentii (Kafferath) Skinner and Torulopsis aeria (Saito) Lodder were dominant,
The species pattern of yeasts in root washings was similar to that in
soil samples collected at the same time.